Practice bomb



Patented June 19, 1934 prev PRACTICE BOMB Yiirgen, Baron Silberg von Stackelberg, Baltimore, Md.

Application November 5, 1932, Serial No. 641,438

7 Claims.

This invention relates to a practice bomb, and more particularly to a practice aerial bomb which may be released from an airplane.

Heretofore, practice aerial bombs have been made and used to a certain extent, but such practice bombs have been found to be highly impracticable and expensive, due to the fact that they did not, and could not be made, with the substitution of cheaper materials, so that they would be identical to a regular battle bomb as regards exterior appearance, contour, weight, visibility of explosion, and center of gravity. Therefore, an aviator using or practicing with such impracticable practice bombs made heretofore, would become highly inefficient in the use of a regular battle bomb.

This invention comprehends the construction of a practice bomb, which may be inexpensively manufactured, yet permitting the manufacture of the same so that it is precisely in accordance with a regular battle bomb, as regards weight,

center of gravity, exterior appearance, contour,

and visibility of explosion.

The primary object of the present invention resides in a very inexpensive construction of a practice bomb so that in exterior appearance, size,

weight, visibility of explosion, and center of gravity, it may be precisely in accordance with a regular battle bomb.

Another object of the invention resides in a practice bomb which may be made from a few simple, inexpensive parts, which will not require the service of a trained explosive expert, or mechanician to make, or assemble the same.

Another object of the invention resides in a practice bomb which may be transported, and handled, without fear of accidentally exploding the same.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the construction, combination and arrangement of parts hereinafter described and then sought to be defined in the appended claims, reference being had to the accompanying drawing which show, merely for the purpose of illustrative disclosure, one embodiment of this invention, it being expressly understood, however, that various modifications and changes may be made in practice within the scope of the claims without digressing from my inventive idea.

In the drawing:

Figure 1 is a vertical sectional view of a practice bomb constructed in accordance with my invention;

Fig. 2 is an enlarged fragmentary view of the tail end of the bomb; and

Fig. 3 is a cross sectional view on the lines 3-3 of Fig. 1.

The invention will be more readily understood 0 by referring to the drawing which is described in detail, as follows; the numeral 1 denotes the elongated body of the bomb which may be formed of cement, concrete, or a similar substance. A moldable plastic or semi-plastic substance 1 for 5 the body is desirable, inasmuch as it is inexpensive and may be molded around a hollow cylindrical tube 2 in a semi-solid or semi-fluid condition which later becomes hardened, and permanently and firmly set thereon. The tube 2 is adapted 7 to contain an explosive A which may be a black powder, or a solid substance, so that when exploded, it indicates clearly and visibly by the effusion of colored smoke. The body portion 1 is preferably annular in cross section and extends throughout a substantial portion of the length of the cylindrical tube 2, and gradually tapers toward the tail end of the bomb, and stops short of the said end thereof to provide for mounting of vanes 11 hereinafter referred to, and has a 8n rounded nose 1. The entire body 1 may be exteriorly coated or covered with a suitable paint or other covering i to present a smooth outer surface.

The body 1 of the bomb has associated there- 5 with, suitable means 4, by which the center of gravity and the weight of the entire bomb may be predetermined, so as to be precisely in accordance with a battle bomb. If a cement or concrete body 1 be used, it is necessary that the means 4 be of a very light nature.

Wooden sticks or blocks or other suitable light material might well be used. As shown, these wooden sticks or blocks 4 are diametrically oppositely disposed with respect to the cylindrical tube 2, and while four such blocks are shown, it is to be understood that a greater or smaller number may be used. These blocks 4, as before Sta-ted, serve as a means to predetermine the weight and center of gravity of a practice bomb so that it may be precisely in accordance with a regular battle bomb. Moreover, it is believed obvious that means other than the means 4 may be used and the same result accomplished. The means 4 is shown as disposed in the body 1 at a point where it is greatest in diameter or cross sectional measurement. It is to be further understood that it is primarily important to so position the means 4 in the body 1 that it balances the entire bomb and the correct center of gravity is obtained. w

In the event a converse construction of the body 1 should be desired, that is, if the body 1 be made of a material lighter than cement or concrete, then, the means 4 must necessarily be of a very heavy nature, and the same result obtained as hereinbefore described.

The hollow cylindrical tube 2 is preferably of metal, and an ordinary gas-pipe has been found to serve the purpose. The tail end of the tube 2 is interiorly screw threaded as at 5 to accommodate the detonator assembly.

The detonator assembly which closes the tail end of the bomb, and which may be attached to the bomb as a single unit consists of a plug 6, preferably of metal, and containing a fulminate cap 7, a cylindrical detonator hammer 8, also preferably of metal, upon which is mounted a suitable propeller 9, a shearing pin 10, of soft copper or a like material, which pin extends through a transverse opening in the plug 6 and the detonator hammer 8, and has its ends bent into engagement with the exterior of the plug as shown, to prevent outward displacement of the detonator hammer, and a cotter pin 16 which extends through an opening in the detonator hammer, as shown. The plug 6 is exteriorly screw threaded as at 6' so as to be adapted for engagement with the screw threads 5 in the tube. The plug 6 is also provided with an interior cylindrical bore 6 with a tapering bottom and a reduced opening 6 which cooperates with the interior of the hollow tube 2. The detonator hammer 8 is adapted for a sliding fit in the cylin-. drical bore 6 and has at one end a tapering portion 8 and a further reduced firing pin 8*. At the other end of the detonating hammer 8, there is an enlarged portion 8 of any suitable outline, and intermediate the said ends, suitable screw threads 8 are formed, upon which the propeller 9 is mounted.

The tail end of the tube 2 has diametrically oppositely disposed outwardly extending vanes 11 secured thereto'preferably as by spot welding 12. Four of such vanes 11 are desirable, but, any suitable number may be used. The nose or forward end of the tube 2 is closed by a plug 13 which maybe of wood, cork, or other suitable compressible material. This plug may be forced to any position in the tube as shown in Figure 1 whereby the amount of powder or other explosive placed in the tube may be regulated. Thisregulation of powder is desirable from an economical standpoint inasmuch as varying amounts may be used according to the altitude from which the bomb is to be dropped. The bomb may be held in the airplane by any suitable or well known means, and I have merely shown a means 14 which extends through the body 1 and is connected to the tube 2 as by welding, or otherwise attached thereto as at 15. This securing means 14 is formed with an eye or hook 1% at itsfree end.

In Figure 1, the hollow cylindrical tube 2 is charged with a suitable explosive A, and the detonator hammer 8 is held in spaced relation to the fulminate cap '7 by means of the propeller 9 which is screw threaded on the threads 8 of the detonator hammer 8 into engagement with the outer end of the plug 6. Therefore, it will be seen that unless the cotter pin 16 be removed, the pin 10 be sheared, and the propeller unscrewed as shown in Figure 2, the charge of explosive cannot be accidentally exploded, and the bomb may be handled and transported in safety.

However, when the bomb is released from an pin 8 will engage the cap 7 causing a percussion or ignition thereof, which in turn, will cause an explosion of the explosive A in the tube 2 and the entire bomb will be torn or exploded to pieces, and the explosive will effuse therefrom a colored smoke constituting a visual signal, indicat ing to the aviator the spot where the bomb has struck.

I have found that the detonator assembly is very often not damaged, and in the event it is found after the explosion, it may be re-used.

From the foregoing, it is believed clear, that I have devised a practice bomb of a few simple inexpensive parts, the said bomb having all of the desired characteristics of a regular battle bomb, and one which an aviator may use in the same manner as a regular battle bomb, and therefore, perfect his marksmanship and ability to make a more perfect hit, precisely the same as if the regular battle bomb were being used.

What is claimed is: r

1. A practice bomb comprising, in combination, a body portion of moldable plastic material molded on a cylindrical tube having an explosive charge therein, means for closing one end of the tube, and the other end of the tube'having associated therewith a detonator assembly with a cap therein, the detonator assembly having a detonationhammer adapted for movement therein toward the said cap, means comprising a propeller mounted on the detonator hammer for, normally preventing engagement of the detonator hammer with the cap, the said propeller being capable of movement during flight of the bomb so as to release the said hammer from restraint so that when the bomb strikes the ground, the impact will cause the said detonating hammer by inertia to engage the said cap and thereby initiate the explosion of the bomb, and means embedded in the said body portion exteriorly of and adjacent the first mentioned end of the tube whereby the weight and location of center of gravity of thebombis predetermined. I

2. In an aerial practice bomb constructionfa body portion, an explosive and smoke producing 130 charge, a tapering plug and a detonating assemblage, which body portion comprises a tubular member provided by a hollow cylindrical metal tube, vanes, and a molded exterior section suitably secured in place about said tube, and with- 135 in said exterior molded sectionand exteriorly in respect to said metal tubesuitable localized sections of a material having physical characteristics different from that of the molded exterior section of the body whereby due to the employment of said localized sections the desired locus of the center of gravity of the bomb is enabled to be realized, the nose or forward end of the tube being closed by the tapered plug when the explosive charge is in place within the tube, the 145 tail or rear end of which tube is interiorly screw threaded to receive and hold an exteriorly screw threaded plug of the detonating assemblage, the vanes being secured as by welding to and along the exterior of the tail or rear portion ofthe 1.56

metal tube, which said detonating assemblage comprises a centrally-bored exteriorly screw threaded plug that fits into the interiorly threaded portion at the tail or rear end of the tube, a detonating hammer having a fit that permits a forward sliding movement within the centrally bored portion of the plug, a propeller, a shearing pin and a cotter pin, which exteriorly screw threaded plug is shaped due to the central bore thereof so as to provide a construction whereby a fulminate cap can be maintained in proper position to be detonated and whereby under proper conditions detonating thereof can be effected by and through means of said detonating hammer, the boring of the plug being such that communication is provided between the place where the detonating of the fulminate cap takes place to the space containing the explosive charge, the detonating hammer and the exteriorly screw threaded plug being provided with openings whereby the shearing pin when extending therethrough can be relied upon to normally hold the detonating hammer rearwardly away from the fulminate cap until such conditions occur under which the shearing of the pin will be efiected as the result of dropping the bomb and the ultimate striking of the nose portion of the bomb against an object, an intermediate portion of the detonating pin being screw threaded at the exterior thereof and the propeller having an internal screw-threaded central or hub section that provides an easy fit as between the propeller and the detonating hammer whereby the propeller will unscrew during a dropping of the bomb, the propeller member being normally positioned adjacent or proximate the rear end of the screw threaded plug, and the detonating hammer having therein an opening for receiving the cotter pin that is relied upon for normally insuring that the propeller remain proximate the rear end of the bored plug, which cotter pin is removed prior to dropping the bomb, the detonating pin having an enlarged head for insuring the maintaining of the propeller on the detonating hammer even after the fan blade has moved rearwardly in respect to the detonating hammer as the result of the unscrewing incident to the dropping of the bomb.

3. In an aerial bomb construction comprising a body portion having therein an explosive and smoke producing charge, and a detonating assemblage; which body portion comprises a hollow cylindrical metal tube, a suitably shaped and weighted exterior section secured to said tube, suitable localized sections of a material having physical characteristics different from that of the said weighted exterior section whereby due to the employment of said localized sections the desired locus of the center of gravity of the bomb is enabled to be realized, a forward closure member for the nose or forward end of said tube, which said closure member is employed when the explosive and smoke producing charge is in place within said tube, and vanes welded to the exterior of the rear section of said tube; which said detonating assemblage comprises a centrally bored plug that is secured to the tail or rearward end of the tube, a detonating hammer that is mounted to slide within the centrally bored portion of the plug, a propeller, a shearing pin, and a cotter pin; which plug is shaped to provide a seat for a fulminate cap whereat under proper conditions detonating thereof can be effected following a forhammer relative to the plug, the boring of the plug being such that communication is provided between the place where the detonating of the fulminate cap takes place to the space containing the explosive charge, the detonating hammer and the bored plug being provided with openings whereby the shearing pin when extending therethrough can be relied upon to normally hold the detonating hammer in rearward spaced relationship in respect to the fulminate cap, an intermediate portion of the detonating hammer being screw threaded at the exterior thereof, the propeller having an internal screw threaded central or hub section that is mounted on said externally threaded section of the detonating hammer, the propeller member being normally positioned proximate the rear end of the centrally bored plug, the detonating hammer having therein an opening for receiving the cotter pin that is relied upon for normally insuring that the propeller remain proximate the rear end of the centrally bored plug, which cotter pin is removed prior to dropping the bomb, and the detonating hammer having an enlarged head at the rear end thereof for insuring the maintaining of the propeller in place thereupon.

4. A detonating assemblage comprising a centrally bored member, a detonating hammer mounted in the bored opening of said member and having a firing pin at the forward end thereof and an intermediate exteriorly threaded section, a fan element or propeller which has an internally threaded central section and which is mounted upon the exteriorly threaded section of the detonating hammer, a shearing pin that passes through the detonating hammer into the centrally bored member and which is relied upon for normally holding the detonating hammer in rearward position but which is constructed so as to permit shearing of the pin and consequent forward movement of the detonating hammer incident to a dropping of a bombto which the assemblage may be appliedfrom a sufficient distance and incident to the striking of the nose of the bomb against an object at the end of the drop, and a removable cotter pin which enters an opening in the detonating hammer and which is relied upon to normally insure the maintaining of the propeller proximate the rear of the centrally bored member until the cotter pin is removed prior to a dropping of the bomb, the bore of said centrally bored member being shaped so as to provide a seat for a fulminate cap to be detonated by a forward movement of the detonating hammer and the consequent detonating of the cap by the firing pin striking the cap, the forward end of said bored member having an opening extending from the said seat whereat the detonation occurs to the forward exterior of the plug.

5. A detonating assemblage comprising an exteriorly threaded centrally bored metal plug, a detonating hammer mounted in the bored opening of said plug and having a firing pin at the forward end thereof an intermediate exteriorly threaded section and an enlarged rear end, a propeller which has an internally threaded hub or central section that is mounted upon the exteriorly threaded section of the said detonating hammer, a shearing pin that passes through the detonating hammer and into the plug and which shearing pin is relied upon for normally holding the detonating hammer in rearward position but which is constructed so as to permit a shearing of the pin and consequent to forward movement of the detonating hammer due to inertia incident to the forward end or nose of a bomb with which in an opening provided in the detonating hammer and which cotter pin is positioned and is relied upon to normally insure the maintaining of the propeller proximate the exteriorly screw threaded plug but which cotter pin is removed prior to a dropping of the bomb, the central bore of the screw threaded plug being shaped so as to provide a section whereat a fulminate capv is supported and held so as to be detonated incident to the bomb striking an object following the dropping of the bomb, the forward end of the plug having an opening extending from the place where the detonation of the fulminate cap occurs to the forward exterior of the plug.

6. A detonating assemblage comprising a centrally bored metal plug, a detonating hammer mounted in the bored opening of said plug and having a firing pin at the forward end thereof and an intermediate exteriorly threaded section, a propeller having an internally threaded central section mounted upon the exteriorly threaded section of the detonating hammer, and a shearing pin that passes from the bored metal plug into the detonating hammer, which shearing pinuntil shearedserves to hold the detonating hammer in rearward position and against rotation,

the central bore of the screw threaded plug being shaped so as to provide a section whereata fulminate cap can be supported and held so as to be detonated by the firing pin incident to forcible forward movement of the detonating hammer, the forward end of the plug having an opening from the place where the. detonation occurs to the forward exterior of the plug.

'7. A practice bomb comprising, in combination, an elongated body portionof annular cross section, a cylindrical tube extending through and having one end thereof projecting beyond one end of the said body portion and having an ex plosive charge therein, a unitary detonator assembly attached to and closing the extreme end of said projecting end of the tube, vanes secured to the said projecting end of said tube at diametrically opposite points thereon and extending outwardly therefrom, said vanes extending substantially from the terminus of the said end of the body portion to substantially the end of the projecting portion of the tube, means embedded in the said body portion exteriorly of and adjacentthe other end of the tube whereby the weight and location of center of gravity of the bomb is predetermined, and means for closing the last mentioned end of said tube.

YURGEN, BARON SILBERG VON STACKELBERG. 

